how many hp would I get if I install a turbo on the 840 4.4

Depends on How far you are willing to go with it. The compression on the M62 is too high to safely run no more that 7 PSi of boost. Which will give you about 115 HP more. But you can lower the compression to 8:1 or close and run high boost to get more. And you can do other stuff to get even more.

So the question is "How deep is your pocket"?

[being a smug jerk]
The fact that you are even asking the question means you need to research things more. Considerably more.
[/being a smug jerk]

Look, the question you are asking doesn't really have an answer because you don't give enough specifics to make a good guess. Such things as:

What kind of turbo?
Intercooled?
Boost level?
Turbine housing?
What kind of tuning?
Bottom mount, or (blech) rear mount?
Exhaust setup?
Injectors?

..and so on. That's just for starters. You may as well ask "How much hp will I get if I add another engine?" Your question shows that you haven't looked into this very much at all. I'm not trying to be mean, I'm just trying to explain why your question makes no sense.

Hey Ahmed,

How much would it cost to get the 115h that you are talking about?

Moon, There is no aftermarket Turbo kit available for the M62 engine. You will have to do all the research and development yourself and I can help a bit. However there are a couple of tuners who sells Supercharger kits for the 540 and 740 for around $6500. Those could be fitted to the 840 with some minor modifications (Bracket redesign, A/C lines redirection, etc) to get upto 411 HP.

ESS Tuning Supercharger (http://www.esstuning.com/default.asp?c=shop&cat=93&subcat=159&subcat2=162&id=)

VF Engineering Supercharger (http://www.vf-engineering.com/kit_bmw_e38_740-97-01.php)

But you may have to do a lot of the work yourself to save any considerable amount of $$.

Ahmed- about the max boost with stock compression- some of the E36 guys have taken the S50/52 up to 14psi with stock everything for extended periods on pump gas. The tune has to be just right, though. I think they finally bent a rod while in the high teens for boost using race gas.

So, you may actually be able to do more than 7psi, if the sleeves can take the boost. Of course, some form of aftercooler and a very good tune will be the key requirements for keeping the stock CR and upping the boost, but you get the idea.

Also, the ESS and VF kits can (I think) be combined with the RMS aftercooler to keep the IAT's down. At least, they have been for the E36 guys, so I would think that the hard part would be doing some creative placement and running the lines. Some of the VF E36 guys are running 11psi with just the cooler, stock compression.

xatlas0...you are correct that the M62 may be able to take more boost. Actually the M60 4.0 is able to take more boost than the M62 4.4 as the M60 has more meat between the cylinder walls.

But my camp of thought is "Safely" with everyday drivability for someone who is not savvy with tuning or checking and adjusting the AF Ratio or monitoring the Air temp. I have seen M62 take considerably more boost with the help of Air to water Aftercooler + Aquamist + a good weather day.

I have seen M62 take considerably more boost with the help of Air to water Aftercooler + Aquamist + a good weather day.

Sounds like there's a fun story behind that.

how many hp would I get if I install a turbo on the 840 4.4

Moonslook,

What year is the 840Ci? If it is a 1994 840Ci your car probably has a M60 = 4.0 engine vs. a M62 = 4.4.

S/C it! Several companies: ESS Tunning, VF-Engineering & others (Vortech Charger) that make a 540 S/C kit w/ some mods it will work! 124 hp gain! $6K to 8K before installation!

I DID NOT READ FUTHUR DOWN!

840ways to C :redspot

Sounds like there's a fun story behind that.

LOL. The moral of that story is "You can not run Race Gas tuning on a really Hot day especially if you fill up with Pump gas". :nono:nono

I am sure you get it:):)

Ahmed,
you are right . my 840 is 4.0 , do you mean that it might work better than a 4.4. one more question: would i feel any deffrence between the 4.0 and the 4.4? the reason i am asking that i have another 97 840 that has a 4.4 on it and i am using it for parts because it is not fixable( hit very hard on the r side) plus i am not seeking more than 360 hp. so what do you think?

Ahmed,
you are right . my 840 is 4.0 , do you mean that it might work better than a 4.4. one more question: would i feel any deffrence between the 4.0 and the 4.4? the reason i am asking that i have another 97 840 that has a 4.4 on it and i am using it for parts because it is not fixable( hit very hard on the r side) plus i am not seeking more than 360 hp. so what do you think?

Moonslook.....Once again there are a lot of Variables. First of all an assessment needs to be done to measure the condition of the 4.0 M60 engine. A lot of the M60 engines in the US were affected by the high sulpher content in the gasoline which ate away the Nikasil coating in the cylinder walls. The 4.4L M62 did not have that issue. A compression test should provide the health of the cylinders. If they are good you can then go with it. The Bore/Stroke of the 4.4L is 82.7mm / 92mm and of the 4.0L is 80mm / 89mm and they are both 90° V-Engine. So you may be able to run a little more boost on the M60 than the M62. But if you are after roughly 400 HP it does not matter which engine you use. I recommend staying with the M60 (Provided it has good compression) as it is run by OBD I programming and easier to tune, not to mention the cost and hassle associated with the engine transplant (Tranny will not match up, driveshaft issues, etc.). Also the M60 has a more aggressive cam profile than the M62.

When I had my 840, I did a lot of research on this and almost bought the ESS brand. If I was in California, I would have selected VF Engineering.

Here is the SC 840 that a friend of mine did. He since sold the car and moved on to a Lotus world. (http://members.roadfly.com/faisal_in_laurel/HellRaiser.pdf)

Ahmed,
you are right . my 840 is 4.0 , do you mean that it might work better than a 4.4. one more question: would i feel any deffrence between the 4.0 and the 4.4? the reason i am asking that i have another 97 840 that has a 4.4 on it and i am using it for parts because it is not fixable( hit very hard on the r side) plus i am not seeking more than 360 hp. so what do you think?

The 4.4 has an extra 10% displacement. The 4L, in stock trim, put out about 260rwhp/290lb-ft. The 4.4, on the other hand, especially if it is a non-VANOS version, put out considerably more, to the tune of 280-290rwhp and 300+lb-ft of torque. You can see some of the dyno plots of such engines in the E39 5-er section of this board, if you'd like.

When you say 360hp, do you mean crank or wheel hp? There is a 4.6L version of the M62 (the 4.4L engine) that puts out, according to BMW, 360hp. It was used in the X5. Another member on this board put in such an engine and a 6 speed in his 740, says it's a riot. You could try that and some cams, that would likely get you around 320, 330 rwhp, which is about 380 crank hp.

Supercharging it would be a far easier solution than trying to brew your own turbo kit, like Ahmed is suggesting. e31bubba is, last I recall, attempting to modify the ESS or VF kit to fit the E31, much like is being suggested to you. Hopefully, he'll chime in soon.

Ahmed-
Yeah, that sounds like a very bad time for the owner.

If your looking at 360 at the crank that shouldn't be too hard Wokke chip gets you to 326hp Use cat cams, port the heads, bore the tb and buy a cda. have you right around 350-360hp crank though not rwhp. Your still looking at upwards of 5k i believe last time i priced a set of cat cams it was around 3500-4000 just for the cams not to mention valve springs labor etc.

Trust me...........FI is the way to go and S/C's are the weapon of choice with the V8...........